In this article:


Juices and juice cleansing are a popular trend, touted for their detoxifying, weight loss and health benefits, which promise to stimulate you by providing a daily dose of fruit and vegetables. There is an abundance of options, from a few bottles to take with you to cleaning products that replace food for a week. Is this trend really true to its predicted effects? Is there a difference between making juice and blending? Although juice can increase fruit and vegetable intake, it may not be as glamorous as it sounds – it can even be dangerous if it becomes a continuous habit.

What is Juicing?

Juicing is a process whereby juice is extracted from fruits and vegetables, for example by pressing or pressing. This is different from eating whole fruits and vegetables or mixed drinks, because juice only remains liquid and discards the fiber-filled pulp. (1) More information about the importance of fibers in the constipation article of this issue on page 10 of this issue. According to the US Department of Agriculture (USDA), it is recommended that half of the plate consists of fruit and vegetables. (2) Juicing offers a way to simplify these daily needs, since one bottle can contain extracts from multiple fruits and vegetables and is quick and easy to consume.

Juicing versus Blending

Benefits of Blending Cons of Blending
Unlike juice, blending preserves all edible parts of the fruit or vegetable in the drink. A study from 2014 published in Preventive nutrition and food science discovered that mixed drinks consisting of apples, pears, persimmons and mandarin oranges showed a stronger antioxidant activity and greater amounts of phenolic compounds than prepared by juice. (3) Phenolic compounds are molecules that contribute to antioxidant activity that have been shown to be inversely correlated with the risk of chronic diseases if they are abundantly present in the diet. (4)

Because mixed drinks contain all the fibers of the original fruit and vegetables, they can quickly contribute to excess fiber if a person's diet is not properly controlled. Too many fibers can lead to intestinal gas, a bloated stomach and cramps. Water intake must also increase in addition to increased fiber intake to promote bowel movements. (5)
Benefits of Juicing Cons of Juicing

In the 2014 Preventive nutrition and food science The results of the study showed that the level of ascorbic acid or vitamin C was higher in drinks prepared by making juice instead of blending. In particular, the juice of apples, pears and mandarin oranges contained the most ascorbic acid content. (3) Thus, nutrient and antioxidant levels, such as vitamin C, may differ based on juice extraction techniques.


Because juice removes the peel from fruit and vegetables, it also removes fiber but retains all sugars. (7) Consider, for example, a fresh, medium-sized apple with 19 g of sugar and 4 g of fiber. For comparison: a glass of apple juice contains no fibers and can contain juice from several apples, which increases the total sugar content (1 cup of apple juice contains approximately 24 g of sugar). (8) Because fiber is needed to regulate blood sugar levels, drinking fruit juice can lead to blood sugar spikes. (9) In addition, fiber is also needed to activate satiety reactions, so drinking a cup of fruit juice may not be as filling as eating a piece of fruit. (8)


A study from 2011 published in Nutrition Journal discovered that people who drank 16 oz of carrot juice every day for 3 months significantly increased the total antioxidant capacity in their blood plasma, meaning that there was an increased antioxidant activity in their bloodstream (similar to the effects of mixed drinks). (6)


The fructose present in fruit juice can be problematic because it is associated with increased triglyceride formation in liver cells. Triglycerides are a form of fat that can result from the breakdown of fructose in the liver. Elevated triglycerides can affect liver function and accumulate as plaque within the vessel walls when released into the bloodstream. Because higher intake of fructose is associated with obesity and heart disease, drinking fruit juice in moderation can limit these risks. (10) Dietary guidelines for Americans do not recommend more than one serving or 100 ml of fruit juice as part of daily fruit intake. (11)

Juice cleaning

1. What is it?

Juice cleaning is a process where a person only consumes vegetable and fruit juices for a period of 3 to 10 days. (12) However, there are also juice cleaners on the market that last only 1 day. Some juice cleaning regimes also suggest that no other additional food products are needed during the process.

2. Effects

A study from 2009 published in Proceedings of the Nutrition Society discovered that consumption of the equivalent of 5 servings of fruit and vegetables in the form of puree and fruit juice concentrates intermittently over a period of 8 hours, increased dietary phytochemicals, micronutrients and plasma antioxidant status. (7) Like antioxidants, phytochemicals have antioxidant-like functions that can help ward off disease. (13) In addition, the micronutrients in juices are essential for the maintenance of tissue function. (14)

Many juice cleaning companies state that no additional food is needed to supplement the juice cleaning. However, as mentioned earlier, juice can have an increased sugar content and does not contain the fibers that are originally present in whole fruits and vegetables, causing you to suffer hunger and cause sugar spikes. When the blood sugar level is high, red blood cells stiffen and disrupt blood circulation, which over time leads to an accumulation of cholesterol in blood vessels. (15) In addition, juice cleaning can contain very few proteins because fruit and vegetables generally do not contain as many proteins as animal meat, legumes or dairy products. It is therefore possible that full day cleaning does not meet the daily recommended nutritional value of 46 g protein for women and 56 g for men. (16) Although one day is unlikely to cause damage, several days of juice cleaning can lead to protein deficiency.

Sometimes a cleansing contains a bottle of nut milk in the regime that can explain some of the missing proteins, fibers and healthy fats, but this is usually not sufficient to reach the recommended daily amount. Nuts are also an incomplete protein source, meaning they lack some essential amino acid building blocks that are needed for a healthy diet. (16) Consequently, these missing nutrients from juice cleansing can be responsible for the fatigue and headache reported by some users.

Bottom line
Juicing can be strongly promoted by the media, and there may even be some benefits because you include more fruits and vegetables in your diet. In reality, however, drinking a lot of juice or only cleaning juice can have a number of adverse effects. The lack of fiber, protein and increased sugar consumption during juice cleaning can lead to sugar crashes and make you hungry and tired. In addition, drinking fruit juice too often can increase blood sugar and triglycerides in the long term. Although drinking fruit and vegetable juices that contain vital nutrients has been shown to increase overall antioxidant activity in the body, it can be considered healthier to consume fruits and vegetables in their original form as part of a balanced intake.


  1. Juicing for health and weight loss. WebMD. (2014).
  2. Which foods are in the fruit group? (2014).
  3. Effects of chronic and acute consumption of fruit and vegetable puree drinks on vasodilation, risk factors for CVD and the response as a result of the eNOS G298T polymorphism. P Nutr Soc. (2009).
  4. Vegetable polyphenols as antioxidants in food in human health and disease. Oxid Med Cell Longev. (2009).
  5. Antioxidants. (2014).
  6. Hernandez-Reif, M, et al. Lower back pain is reduced and range of movement is increased after massage therapy. International Journal of Neuroscience. 2001; 106 (3-4): 131-145.
  7. Sajedi, F, et al. How effective is Swedish blood glucose level massage in children with diabetes mellitus? Acta Medica Iranica. 2011; 49 (9): 592-7.
  8. Kaye, AL, et al. The effect of deep-tissue massage therapy on blood pressure and heart rate. Journal of Alternative and Complimentary Medicine. 2008; 14 (2): 125-8.
  9. Nutrition and healthy eating. (2012).
  10. Drinking carrot juice increases overall antioxidant status and reduces lipid peroxidation in adults. Nutr J. (2011).
  11. Normal intake of fruit juice predicts central blood pressure. Appetite. (2015).
  12. The benefits of fiber: for your heart, weight and energy. (2014).
  13. Is fructose bad for you? (2011).
  14. Guidelines for healthy drinks. (2009).
  15. Juicing is not all juicy. Am. J. Med. (2013).
  16. Neuroprotective potential of phytochemicals. Pharmacogn Rev. (2012).
  17. Micronutrients in health and disease. Postgrad. Med. J. (2006).
  18. Why high blood sugar is bad. (2011).
  19. Protein. (2012).

By Catherine Hu, BS Candidate, UCLA 2015
UCLA Student Welfare Commission Total Wellness Magazine, Staff Writer

Leave a Reply

Your email address will not be published. Required fields are marked *